What drives thermohaline circulation?

Thermohaline circulation is primarily driven by changes in water temperature and salinity, which together determine the density of ocean water. This dense water sinks in specific regions, typically at higher latitudes where it is cooler and saltier due to processes such as sea ice formation, which increases salinity as ice forms. The variations in density resulting from these temperature and salinity differences create a global conveyor belt of ocean currents. This circulation is essential for regulating Earth's climate and distributing heat across the planet.

The significance of temperature and salinity becomes evident considering how they influence the physical properties of seawater. Warm water is less dense and remains at the surface, while cold, salty water sinks, establishing a flow that is part of a larger interconnected system of ocean currents. Therefore, this balance of temperature and salinity changes plays a critical role in driving the thermohaline circulation.